What must a player do to avoid being penalized for offside?

To avoid being penalized for offside, a player must be onside at the moment the ball is played by a teammate. This means that the player must have at least two opponents between themselves and the goal line (usually the last defender plus the goalkeeper) when the ball is kicked. Being onside allows the player to legally participate in the play as the ball is played, ensuring that they are not gaining an unfair advantage.

This rule is fundamental to maintaining fair play in soccer, as it prevents players from simply waiting near the opponent's goal for an easy chance to score. Recognizing when a player is onside is crucial for both players and referees to properly enforce the offside rule during a match. The other options, while they touch on aspects of gameplay, do not specifically address what a player must do at the moment the ball is played to avoid being offside.